Sewing machine



D86. 25, 1945. I sMlTH 2,391,519

SEWING MACHINE Filed Jan. 5, 1942 I 4 Sheets-Sheet 1 INVENTI'OR. CLARENCE 6: SMITH A TTQHNEY. 4

C. C. SMITH SEWING MACHINE Dec. 25, 1945.

Filed Jan. 5, 1942 4 Sheets-Sheet 2 m ENTOH. CLARENCE CJ/f/Th ATTORA Y Dec. 25, 1945. c. C. SMITH 2,391,519

SEWING MACHINE Filed Jan; 3, 1942 4 Sheets-Sheet s IINVENTOR. CLARENCE c. .sM/m

' ATTORN Dec 25, 1945. c; c. SMITH 2,391,519

SEWING MACHINE Filed Jan; 5, 1942 4 Sheets-Sheet 4 1:11: 2 mill/ll 9:

INVEN TOR. CLARENCE 6. SMITH BY 4f ATTORN Y.

Patented Dec. 25, 1945 2.391.519 SEWING MACHINE Clarence C. Smith, Chicago, Ill., assignor to Union Special Machine Company, Chicago, 111., a corporation of Illinois Application January 3, 1942, Serial No. 425,497 14 Claims; (.01. 112-200) This invention relate 'to an improved sewing. machine construction and more particularly to the provision in machines of this character of improved devices for unlocking and shifting the loopers to a position in which they are rendered ating or control means for the looper unlocking and shifting devices at a convenient point preferably exterior of the housing of the machine. Moreover, it enables the preservation of theoil tightness of the. housing by the appropriate lo-.- cation of the operating or control means.

A special feature of the invention is in the particular construction and arrangement of the connections from the main drive shaft of the machine to the loopers, for operating thelatter, and in the provision of simple manual means for acting upon or modifying these connections whenever it is desiredto render the loopers accessible.

A further object of the invention has been to provide looper unlocking means of atype which will not add tothe weight of the loopers themselves nor to the parts which must'beoscillated' and reciprocated at the distal end of the loo-per shaft. In a machine of the character to which a.

the improved construction is preferably applied, the loopers and looper holders at the distal end of the looper shaft are oscillated in performing their loop-takin functions and are reciprocated for needle-avoid purposes. These oscillations and reciprocations take place at high speed. It is an important feature of the present invention, therefore, that the parts subjected to such high speed oscillation and reciprocation are of relatively light construction.

Other objects,'features and advantages of the invention will appear from the detailed description of an illustrative form of the same which will now be given in conjunction with the accompanying drawings, in which:

Fig. l is a side elevation of the illustrative m-a-' chine, a portion of the frame or housing being broken away to disclose some of the interior mechanism. r

Fig. 2 is a vertical central section through the work supporting arm and connected portion of the frame.

f Fig. 3 is a fragmentary viewqin vertical section, showing a portion of the mechanism illustrated in Fig. 2 but with some of the superposed parts removed. t

Fig. 4 is a transverse vertical section through the work supporting arm of the machine, showing the loopers'in their normal operative position.

Fig. 5 is a view similar to Fig. 4 but shows the loopers in unlocked position and rendered accessible for threading purposes.

Fig. 6 is a detail view, partly'in elevation and partly in vertical section, through the sewing head of the machine, the parts being. shown at a different point in the cycle of the machine from that illustrated in Figure 1.

Fi 7 is a vertical section through aportion of the frame of the machine, showing the connections between the maindrive shaft and the looper shaft in normal operative position. v a

Fig. 8 is a view similar to Fig. '7 but shows the specified connections in unlocked or shifted position.

Fig. 9 is a detail view partly in elevation and partly in section, illustrating a portion of the looper operating connections in normal operative position, and

Fig. 10 is a view similar to Fig. 9 showing the parts in unlocked or shifted position. I

The illustrative machine in which the improved mechanism has been incorporated is of the type disclosed in the Christensen et a1. Patent No. 1,741,095, granted December 24, 1929. Certain of the details of construction of the machine have been omitted from the present case and reference may be had. to said Christensen et al. patent for a full disclosure of these. 7

Referring now to the drawings, the machine may suitably be provided with aframe forming. an enclosing housing for substantiallyall of the operating means. This frame may include a base member I0 which is adapted to be supported on the top of a table and'which carries at its upper end a horizontally extending main frame member l. At one end of the member H there is provided a laterally projecting portion I2 which carries a needle head l3. Members I2 and I3 c onstitute the sewing head of the machine. At the opposite end of the member II is a downwardly extending member 14, forming a vertical standard, from the'lower end of which projects a work supporting arm l5. 'The free end of this arm extends beneath the needle head.

Within the needle head there is provided a vertically reciprocable needle bar It carrying one or more needles I? at its lower end. Three needles are shown, but the number employed may be varied as desired. Adjacent the needle bar there is also mounted for reciprocation in the needle head a presser bar I8 carrying at its lower end a presser foot IQ, of any suitable construction. Within the work supporting arm ,I 5,, adjacent its free end, there is provided for cooperation with the members on the sewing head one or more loopers 20, three being shown, and a Workfeed dog 2|, of any suitable construction. The feed dog has a portion adapted to pass through openings in a throat plate 22 at the top of the work supporting arm. Provision is thus made for .advancing the work along and off the end of the work supporting arm and for forming desired lines of stitching as the work is advanced.

Power for operating the stitch-forming and work-feeding devices is supplied to the machine through .a combined pulley and hand wheel :23, which may be connected by a belt with any suitable source of power,:suchras:a motor (notshown) appropriately mounted beneath the supporting table. The pulley '23 :is secured to a shaft 24 journaled in suitable bearings provided in the main frame member :Il. Shaft 24 extends substantially the full length of the frame member i I but for convenience of assembly is preferably formed in two sections, which are connected together by a coupling 25. Collars 26, secured to the shaft at opposite sides of the coupling, serve to retain it in proper longitudinal position and take the end thrusts imparted to'the shaft.

Within the sewing head the shaft 24 is provided with an eccentric portion .21 connected by a pitman 28 with a bell crank lever 29 carried by a shaft 30. A forwardly extending arm of the bell crank is connected by a link 31 with an arm 32 s cured to the needle bar 16. In this way the needle bar is reciprocated upon each revolution of the shaft 24. Presser bar 18 is urged downwardly by a spring '33 into yielding engagement with the work on the work supporting arm. The tension of the spring may suitablybe varied by a thumb screw 34. Any suitable means may be employed for lifting the presser bar against the action of the spring 3'3, under manual, knee or foot 'control. Suitable devices for this purpose arepart- 1y illustrated in Fig. 6 and include a bell crank .35 adapted to be connected with any appropriate operating means. Since :the details of this mechanism form no part of the present invention, they will notice further described.

The means for operating the feed dog may be of any suitable construction and will be but briefly described. Feed dog 2| is suitably secured by means of a screw 36 to a bar 3! pivotally mounted at 38 on the upper end of a link 39. This link is carried-at the end of one arm of a twoarmed lever 40, rockably mounted at '4! within the work supporting arm. The rearwardly ex tending arm of the lever 40 has a ball'and socket connection at 42 with an upwardly extending rod 43 carrying at its upper end an eccentric strap 44 cooperating with an eccentric on the shaft 24. Operation of this eccentric causes the bar 3! and the attached feed dog to be lifted and lowered at appropriate points in the cycle of operation of the machine. Atthe same time another eccentric on the shaft 24 cooperating with an eccentric strap 45 serves to impart longitudinal, reciprocatory movements to the bar 37. The connections for this purpose include a rod 46 attached to the strap 45 and connected at its lower end with a ball stud carried by an arm 4! of a rock member 48 pivotally mounted at 48a on the frame. A slotted plate 49 forming part of the rock member 48 is connected by a link 50 with an arm 5| mounted for rocking movement upon a stud 52 carried by the work arm member of the frame. The rear end of the bar 31 is attached to the arm 5| which thus reciprocates the bar. The length of the feed stroke imparted to the bar 31, and hence the dog 2 I, maybe variedby adjusting the position of the stud 53 in the slot 54 of plate '49.

The loopers 20 are secured by screws 55 to a holder 56 attached to the end of a shaft 5'! by means of a clamp screw 51a. Looper shaft 51 (Figs. 1, 2.and 3) is suitably mounted in bearings 58, 59 and B0 in the work supporting arm of the frame for both oscillation and longitudinal reciprocation. To impart longitudinal, reciprocatory movement :to the looper shaft, for needleavoid purposes, the shaft is provided with a pair of spaced collars 6| and 62 which-are secured thereto between the bearings 59 and fill. Between these spaced collars a sleeve :63 is freely mounted. This sleeve is held against relative longitudinal movement along the shaft by the fixed collars BI and 62 but thesha-ft is free to rock within the sleeve. A downwardly extending fork 64,integral with the sleeve 63, straddles a flat-sided portion 65 of a pin 66 mounted in the work arm, thus preventing rotation of the sleeve while permitting bodily movement of the same with the shaft 5! relative to the frame. A stud 61 extendinglaterally from the sleeve 63 is connected by a screwthreaded link 68 with a-stud 69 carried by an arm 10 integral with the rock member 48. Stud 69 may be adjustably secured to the arm 10 at any desired point along aslot H in the arm. By appropriate adjustment of the stud 69-, the ex tent of the longitudinal, needle-avoid movement imparted to the shaft 51 may be varied as desired. Moreover,'by appropriate adjustment of the link 68, which .is provided with right and lefthand threads, respectively, at its two ends, the position of the loopers may be varied to aline them correctly with the needles.

The oscillating, or loop-taking and loop-shedding, movements are imparted to the loopers by the oscillation of the shaft 51 in the manner now to be explained; At its rear end the shaft 51 carries an integral crank arm 12, having a crank pin 13 connected by apitm'an designated generally at 14 with a crank portion 15 at the rear end of the shaft 24. This connection is such that upon each rotation of the shaft 24, the crank arm 12 will be rocked and will produce oscillation of the shaft 51 and the loopers through a predetermined arc. The construction is such, furthermore, as to bring about the conversion of rotary to oscillatory movement between shafts contained in vertical planes which are disposed at an angle to each other.

To enable the loopers to be unlocked and shift ed outwardly beyond the normal range of. oscillation and into a more accessible position, the link 14 is formed in several parts. It includes a yoke or strap member 16 mounted upon the crank pin 13 and adapted to receive the lower, screw-threaded end of a rod ll. At its upper end this, rod has screw-threaded engagement with a member 18. A look. nut 19 serves to lock the rod I1 and member 18 in a desired relative position. By the use of right and lefthand threads, respectively, at the two ends of the rod 11, the normal effective length of the link 14 may be varied and thus the position of the are through which the shaft 51 and the loopers will be oscillated may be altered. Member 18 is pivotally connected at its upper end, by--means of'a pin 80, with an arm 8| extending downwardly from' a yoke or strap 82 surrounding the crank arm 15. A leaf spring 83 secured by a pin 84 between spaced portions of the member 18 normally bears, at its upper end, against a fiat edge surface 85 of the arm BI, and urges a shoulder 86 on arm 8| against a shoulder 81 on member 18. This normally serves to hold the member 18 and arm 85 in alinement for transmission tothe crank arm 12 of the substantially vertical component of the movement of crank I5. However, the toggle joint formed by member '18 and arm 81 may be broken and these parts may be shifted into an angled relation with respect to each other. Spring 83 is adapted then to bear against a flat surface 88 at the lower end of arm 8| and thus retain the toggle in its broken or altered condition.

Breaking or modification of the toggle connection is effected as follows: An arm '89 extending laterally from the yoke or strap 82 is adapted to be engaged by the lower end of a pin Bil mounted for vertical reciprocation in a socket 9! carried by the top of the main frame H adjacent its rear end. A spring 92, within the socket, normally urges the pin upwardly until a collar 93, secured thereto, engages the bottom of the socket, as'

shown in'Fig. 7. However, the pin may be depressed, whenever desired, bymanual operation of a knob 94 at its upper end. When depressed, the pin acting upon the arm 89 breaks the toggle and causes it to shift from the Fig. 9 to the Fig. 10 position. Spring 83 at this time shifts the parts slightly beyond the position to which they are rocked by the pin. This causes the loopers to shift from the Fig. 4 to the Fig. position. A hinged cover 95 is provided adjacent the end of the work supporting arm to give access to the loopers and to allow for this extra movement of the loopers in-to unlocking position. It will be understood that the hand wheel 23 may be turned to bring the loopers into their most accessible, i. e., extreme loop-shedding, position if the machine has not been stopped in this position;

said-connections to cause said looper to be carried beyond'said 'pre-determined are into readily accessible position. i 2. In a sewing machine, stitch forming devices including a looper, a long oscillatable shaft havsaid'looper rigidly secured thereto adjacent one end thereof and adapted to impart to said looper its loop-taking and loop-shedding movements, a drive shaft, modifiable connections therefrom to a point on said oscillatable shaft remote from said looper for oscillating. the same and said looper through a pre-determined are upon each revolution of said drive shaft, a housing enclosing said connections, and means operable exteriorly of said housing for modifying said connections to cause said looper to be carried beyond said pro-determined are into readily accessible position.

- I 3. In a sewing machine having a frame with a vertical'standard portion, an overhanging sewing head portion, and a free-ended work supporting arm extending laterally from said standard portion with its free end beneath-said sewing head, and having a-reciprocable needle bar in said sewing head, a needle carried thereby, a

looper shaft extending longitudinally of said arm, a looper at the distal end of said shaft adapted to cooperate with said needle, and a drive shaft extending into said standard, the combination of When the loopers have been re-threaded, they construction and arrangement of the severalparts without departing from the general principles and scope of the invention.

What I claim is: I v

1. In a sewing machine, stitch formingdevices including a looper, a long oscillatable shaft'having said looper rigidly secured thereto adjacent one end thereof a d adapted to impart to, said looper its loop-taking andloop-shedding movements, a drive shaft, modifiable I connections therefrom to a point on said oscillatable shaft remote from said looper for oscillating the same and said looper through a pre-determined are upon each revolution of said drive shaft. and means manually operable at will for modifying modifiable connections in said standard from said drive shaft to said looper shaft for oscillating the latter through a pre-determined arc, and

means operable at will to engage and act on said connections for modifying the same and rocking said looper shaft beyond said pre-determined are.

- 4. In a, sewing machine having a frame with a vertical standard portion, an overhanging sewing head portion, and a free-ended work supporting arm extending laterally from said standard portion with'its free end beneath said sewing head; and having a reciprocable needle bar in 7 said sewing head, a needle carried thereby, a looper shaft extending longitudinally of said arm, a looper at the distal end of said shaft adapted to cooperate with said needle, and a drive shaft extending into said standard, the combination of modifiable connections in said standard from said. drive shaft to said looper shaft for oscillating the latter through 'apre-determined are, said connections being adjustable to vary said predetermined arc, and means operable at will to act on said modifiable connections for rocking said looper shaft beyond said pre-determined arc.

5. In a sewing machine having a frame with a vertical standard portion, 'an overhanging sewing head portion, and. a free-ended work supporting arm extending laterally from said standard portion with its free end beneath said sewin head, and having a reciprocable needle bar in said sewing head, a needle carried thereby, a looper shaft extending longitudinally of said arm, a looper at the distal end of said shaft adapted to cooperate with said needle,,.and a drive shaft extending into said standard, the combination of modifiable connections in said standard from said drive shaft to said looper shaft for oscillating the latter through a pre-determined arc, and manually operable means having a portion extending outwardly from said standard adapted to modify said connections and rock said looper shaft beyond said pre-determined are.

6. In a sewing machine having a frame with a vertical standard portion, an overhanging sewing head portion, and a free-ended work supporting arm extending laterallly from said standard portion with its free end beneath said sewing head, a'n'dhaving a reciprocable need-1e bar in said sewing head, a needle carried thereby,a looper shaft extending longitudinally of said arm, a looper at the distal end of said shaft adapted to cooperate with said needle, and a drive shaft extending into said standard, the combination of modifiable connections in said standard from said :drive shaft to said looper shaft for oscillating the latter through a predetermined arc, and a manually operable plunger at the top of said standard normally out of the path of movement of said connections, said plunger when depressed being adapted to engage said connections to modify the same and rock said looper shaft beyond said pre-determined arc.

7. In a sewing machine having aframe with a vertical standard portion, an overhanging sewing head portion, and a free-ended worksupporting arm extending laterally from said standard portion with its free end beneath said sewing head, and having areciprocable needle bar in said sewing head, a needle carried thereby, a looper shaft extending longitudinally of said arm, a looper at the distal end of said shaft adapted to cooperate with said needle, and a drive shaft extending intosaid standard, means in said standard including a pair of pivotally connected links for connecting said looper shaft with said drive shaft to oscillate said looper shaft, spring means interacting between said links .for retaining said links in either of two relative positions, and means operable manually at a said looper shaft through a pre-determined arc,

and manually operable means adapted for actuation exteriorly of the standard to engage and act upon said first-mentioned means to modify the same and rock said looper shaft beyond its normal range of oscillation.

9. In a sewing machine a Work support, a throat plate in said support, a looper beneath said throat plate, a long looper shaft carrying said looper adjacent one end thereof, modifiable means remote from said looper for oscillating said looper shaft through a predetermined arc to impart loop taking and loop-shedding movements to said looper, and manually operable means readily accessible for actuation at a point above the plane of said throat plate adapted to act upon said first-mentioned means to modify the same and rock said looper shaft beyond its normal range of oscillation.

10. In a sewing machine a frame structure including an enclosed hollow chamber, a rotatable main shaft extending into said chamber, a looper shaft extending into said chamber, connections comprising a toggle-like pitman within said chamber extending from said main shaft to said looper shaft for imparting oscillations to the latter, and manually operable means extendin through the wall of said chamber operable to change the effective length of said pitman and thereby shift the looper shaft and a looper car- 'ried thereby to a position in which said looper is rendered accessible for'thre'a'ding.

'11. In a sewing machine a frame structure including an enclosed hollow chamber, a rotatable main shaft extending into said chamber and having an eccentric actuator thereon, a looper shaft extending into said chamber and having a crank arm, a toggle-like pitman extending from said actuator to said crank arm for imparting oscillation 'to said looper shaft, means operable manually at will at a point exteriorly of the chamber for changing the effectivelength of said pitman and thereby shifting said looper shaft to a position where a looper carried thereby is rendered accessible for threading, and means normally operative to hold said manually operable meansv out of the path of movement of said pitman.

12. In a sewing machine having a frame with an overhanging sewing head and a free-ended Work supporting arm extending beneath said sewing head, said frame having a vertically extending'hollow portion from which said arm extends, said machine also having a needle bar reciprocable in said sewing head, a needle carried thereby, a looper in said work supporting arm cooperating with said needle, an oscillatable shaft extending longitudinally and substantially the full. length of said arm and carrying said looper adjacent its distal end, a main drive shaft and connections therefrom for reciprocating said needle bar, the combination of modifiable connections from said drive shaft to said oscillata le shaft within said vertically extending portion of the frame for oscillating said oscillatable shaft through a predetermined arc, and means operable at will exteriorly ofsaid portion of the frame to engage said last-recited connections and modify the same to rock said shaft beyond said predetermined arc.

13. In a sewing machine having a frame with an overhanging sewing head and a free-ended work supporting arm extending beneath said sewing head, said frame having a vertically extending hollow portion from which said arm extends, a needle-bar reciprocable in said sewing head, a needle carried thereby, a looper in said work supporting arm cooperating with said needle, a reciprocable and oscillatable shaft extending longitudinally of said arm and carrying said looper adjacent its distal end, a main drive shaft, and connections therefrom for reciprocating said needle bar, the'combination of connections from said drive shaft for reciprocating said looper carrying shaft longitudinally, alterable connections from said drive shaft to said looper car- .rying shaft within said vertically extending portion of the frame for oscillating said looper carrying shaft through a predetermined arc, and means operable at will exteriorly of said portion of the frame for engaging and altering said last recited connections to rock said shaft beyond said predetermined are without disturbing the other connections recited.

14. In a sewing machine having a frame with an overhanging sewing head and a free-ended Work supporting arm extending beneath said sewing head, said frame having a vertically extending hollow portion from which said arm extends. said machine also having a needle bar reciprocable in said sewing head, a needle carried thereby, a looper in said work supporting arm cooperating with said needle, feed means in said work supporting arm arranged to'feed work along to said feed means and said looper carrying shaft, alterable connections from said drive shaft to said looper carrying shaft within said hollow portion of the frame for oscillating said looper carrying shaft through a predetermined arc, and means operable at will exteriorly of said portion of the frame for engaging and altering said last recited connections to rock said shaft beyond said predetermined arc.

CLARENCE C. SMITH. 

